Proposed enclosures syntax differs from the existing RSS 2.0 enclosures already used by many aggregators.
While we were unable to produce full backward compatibility, we tried to model new syntax as closely as possible to the old syntax so as to ease the migration path for RSS software vendors.
In its simplest form, any existing RSS 2.0 enclosure could be converted to one conforming to this proposal simply by using the appropriate XML namespace as described in section 4.1 and using ``Enclosure'' element name starting with upper case letter.
New syntax should not conflict with the exiting syntax in RSS 2.0, since it uses its own XML namespace. Thus, a feed could contain both old and new-style enclosure definitions.